Improved sealing valve assembly



May 1, 1956 J. E. ECKEL 2,743,905

IMPROVED SEALING VALVE ASSEMBLY Filed Dec. 18. 1952 2 Sheets-Sheet 1 IDRILL STRING "4 DRILL COLLAR --2 BORE HOLE 5 LOWER DRlLL COLLAR FIG.|

John. E. EMzcl nveaov Q 7 abborne i UPPER DRILL COLLAR May 1, 1956 J. E.EcKEL 2,743,905

IMPROVED SEALING VALVE ASSEMBLY Filed Dec. 18, 1952 2 Sheets-Sheet 2 8MOULDED BONDED RUBBER SEAT E HINGE POINT HINGED METAL SEGMENTS 3REMOVABLE CAGE 1 BALL vALvE g FLUTED BALL STOP/ 1 FLUTE FINS f g SEALFIG.-2

John. Fahd) \finveaaor b w Qbtorne United States Patent Oflice 2,743,905Patented May 1, 1956 mrnovnn SEALING VALVE ASSEMBLY John E. Eckel,Tulsa, Okla, assignor to Esso Research and Engineering Company, acorporation of Delaware Application December 18, 1952, Serial No.326,621 3 Claims. (01. 255-28 The present invention is concerned with animproved sealing valve assembly. The invention is more particularlyconcerned with the utilization of this assembly in conjunction withfloating or removable elements, particularly elements of this characterwhich are used in conjunction with well drilling and productionoperations. I A preferred adaptation of the improved sealing valveassembly of the present invention is in conjunction with removable drillcollars wherein the valve assembly comprises an integral part of saiddrill collars. Other specific adaptations of the present invention areconcerned with an improved method for drilling bore holes into the earthsubstrata wherein the improved valve assembly is utilized for theselective removal of drill collars, for the pulling.

of tubing or drill pipe and for the setting of casing. The valveassembly of the present invention comprises a rubthe string is initiallystarted into the well, it is common practice to fill up by pumping mudinto the interior of the'casing to gain weight to sink the string untilsuch .depth is reached that the buoyancy is desirable. This filling upoperation involves considerable delay. It is within the concept of thepresent invention to utilize the present valve assembly to eliminatethis delay. A float collar embodying the present valve assembly will beinstalled in the casing string without the valve ball, thus admittingmud into the casing as long as desired to utilize its weight to sink it.Upon reaching the point at which buoyancy is desired to assist thehoist, the valve ball is pumped down the casing and forced through theflexible hinged membrane, thereby preventing mud from entering thecasing at the bottom thereof and providing the required buoyancy atgreater depths.

Another adaptation of the present invention is in the pulling of thedrill string in a drilling well, or tubing in a producing well, from thewell bore. In manyinstances in the removal of the string from the borehole, it is desirable to seal off the string so as to prevent the flowof fluid into the string as the string is being removed. Heretofore,various means have been used, as for example,

so-called wireline closure valves. These wireline closure valves havebeen lowered to the bottom of the string and the valve operated by anattached wire. By utilizing the improved closure valve of the presentinvention as a. permanent fixture in the string, it is possible to pumpthe ball down to the bottom of the string, seal off the string and hervalve seat reinforced by hinged metal segments molded into the rubber.In operation, the hinged metal segments open under the pressure of aball or similar element activated by fluid pressure in one direction.The ball under counterfiowing fluid pressure will act as a valveclosure.

It is well known in the art to drill bore holes into the earthssubstrata utilizing various techniques. For instance, one technique isto utilize a drill stem or pipe string having attached to the lower endthereof a drill bit. The drill stem is rotated thereby rotating the bit.A drilling fluid comprising an aqueous mud or equivalent material ispassed down usually within the drill stem and passed upwardly in thebore hole between the outer surface of the drill stem and the inside ofthe bore hole. In these drilling operations in order to providesuflicient weight on the lower end ofthe drill stem it is the practiceto utilize drill collar sections within the drill stem above the bit.These drill collar sections are relatively heavy pipe sections andprovide the necessary weight at the lower end of the drill stem.

' As the drilling proceeds it is also desirable to remove one or more ofthese drill collar sections. Heretofore the procedure was to withdrawthe drill stem from the ground, to remove the drill collar, reassemblethe string and lower it again into the ground. This comprises a timeconsuming and very expensive operation. Thus one object of the presentinvention and apparatus is to provide an efficient means of removingselectively one or more of these drill collars from the pipe string.

Another adaptation of the present invention is to use the valve assemblyin conjunction with the setting of casing. In this operation it isinitially desirable to allow the full weight of the casing to besupported by the hoist, permitting the weight of the string to sink itinto the well. When the weight of the string begins to overload thehoist, it is then desirable to float the string of casing into the wellby preventing the entry of mud fluid into the interior of the casing,thus taking advantage of its buoyancy. In conventional casing strings itis customary to install a float valve that prevents entry of mud intothe casing, such valve having a permanently installed ball check. Sincethis valve creates undesired buoyancy when then to remove the stringfrom the well bore.

The present invention may be more fully understood by reference to thefigures illustrating the same. Figure 1 illustrates a drilling stringpositioned in a bore hole and containing at its lower end drill collarassemblies. Figure 2 illustrates the present invention, showing indetail two drill collar assemblies positioned in the drill string.

Referring specifically to Figure l, drill string 1 is shown positionedin well bore hole 2. Suitable means are provided to rotate string 1 fromthe surface. Positioned above drill bit 3 are shown two drill collars 4and 5.

The detailsof construction of these drill collars are illustrated inFigure 2. A drill casing or pipe string 1 is shown positioned in a borehole (not shown). In opera tion, drill casing 1 is rotated preferablyfrom the surface. The lower end of drill casing 1 contains a suitablerotary or fishtail bit attached thereto (not shown). A suitable drillingfluid is passed downwardly within the drill casing 1 which fluid flowsfrom the lower end of the bit and upwardly to the surface through theannulus between the bore hole and drill casing 1.

An 'upper drill collar4 and a lower drill collar 5 are shown positionedwithin drill casing 1. For purposes of simplicity the details of the topof upper drill collar 4 are not illustrated but are the same as thedetails of the top of lower drill collar 5 which are shown in detail.The lower sections of collar 5 are not illustrated but are similar tothe lower sections of collar 4.

The upper ends of the respective drill collars contain a rubber seal 6which prevents the flow of fluid between the outer surface of the drillcollar and the inner surface of the pipe string. Drill collars 4 and 5also contain a satisfactory sealing element 7 as shown. Each of thedrill collars is fitted at its lower end with a removable tubular cage13 which is threadedly attached to the drill collar as shown. A moldedrubber valve seat 8 of generally frusto-conical shape is bonded to theinner surface of the cage 13. The valve seat is reinforced bycircumferentially arranged hinged metal segments 9 that are embedded inthe rubber valve seat and pivotally held by pins 10 that fit intosuitable lugs or brackets (not shown) fastened to the inner wall of thecage 13. Fastened within 3 the lower end of cage 13 is a fluted stopwhose function will be presently explained.

In operation when it is desired to remove the upper drill collar a ball11 is inserted in the drill casing at the surface, through a lubricatingchamber or by other means, and pumped down the casing by normaldirectional circulation. The ball moves down through upper drill collar4 to the rubber seat containing the hinged metal segments 9. Thesesegments move outwardly until the diameter D3 of the seat is greaterthan the diameter D1 of the ball thereby allowing the sphere to passbelow the seat and come to rest on the fluted stop 12 which will notpermit its passage because D2 is less than D1. The ball does notcompletely close off circulation because of liquid passage through theinner fluted fins 14 but does restrict circulation enough to cause arise in the pressure gauge at the surface. This acts as a signal on thesurface that the ball is on bottom.

Normal circulation is then stopped and pressure is applied to theannulus around the drill casing and up through the bit into the lowerbore of the drill casing and drill collar segments. Ball 11 is forcedupward into contact with the seat of hinged metal segments, causing therubber portion and metal hinge segments to move inwardly, therebystopping the upward passage of fluid. Upon closure of the valve seat bythe ball, surrounding pressure forces cause reduction of the diameterD3, preventing upward passage of the ball. The metal segments limitinward and upward travel of the rubber such that inversion of the seatis impossible. Further pressure is applied resulting in the movementupwardly of upper drill collar 4 through the string to the surface. Thelower drill collar 5 has a similar construction at the lower end thereofand can similarly be removed by utilizing a second ball. When thisinvention is applied to drill pipe or tubing to provide a closure meansat the bottom of the string, removable cage 13 and the parts attachedthereto (parts 8 to 14 except 11) are installed as a permanent fittingat the lower end of the string before running said drill pipe or tubinginto the well. Installation of the ball as a closure means is thencarried out as previously described.

The present invention is broadly concerned with an improved valveassembly. It is more specifically concerned with a process and apparatusfor the removal of drill collars from a pipe string. In general thedrill collars comprise a plurality of regular small segments which canbe individually removed as desired, each drill collar segment is of astructure which comprises a hinge flange valve arrangement which permitsa sphere to be forced against the upper surface thereof and causes thehinged elements to move outwardly against the inner wall of the drillcollar thereby increasing the diameter of the valve element andpermitting the ball to pass through.

What is claimed is:

1. An improved valve assembly for bore hole operations comprising atubular member, an inverted frustowithin and fastened to said tubularmember, said valve seat having a central opening at its lower end, aplurality of circumferentially arranged rigid ribs embedded in saidvalve seat material, the upper end of each of said ribs being pivotallyfastened to said tubular member, a ball shaped valve element freelymovable within said tubular member, said valve element having a diametergreater than the opening of said valve seat whereby said ribs will moveoutward to enlarge said opening sufficiently to pass said element when adownward force is exerted thereon but will move inwardly to preventupward return of said element through said opening when an upward forceexerted on said element places said element in sealing engagement withsaid seat, and a stop member positioned within said tubular member belowsaid valve seat and arranged to prevent further downward travel of saidvalve element after it has passed through said opening.

2. Valve assembly as defined by claim 1 wherein said resilient materialcomprises molded rubber.

3. A removable drill collar for a string of drilling casing comprising atubular member adapted to fit slidably within said casing, an invertedfrusto-conical valve seat of flexible resilient material positionedwithin and fastened to said tubular member, said valve seat having acentral opening at its lower end, a plurality of circumferentiallyarranged rigid ribs embedded in said valve seat material, the upper endof each of said ribs being pivotally fastened to said tubular member, aball shaped valve element freely movable within said tubular member,said valve element having a diameter greater than the opening of saidvalve seat whereby said ribs will move outward to enlarge said openingsufiiciently to pass said element when a downward force is exertedthereon, but will move inwardly to prevent upward return of said elementwhen an upward force exerted on said element places said element insealing engagement with said valve seat, a stop member positioned withinsaid tubular member below said valve seat and arranged to preventfurther downward travel of said valve element after it has passedthrough said opening, and at least one resilient seal fixed to theexterior of said tubular member in a manner sealing the annulus betweensaid casing and said tubular member, said seal acting in conjunctionwith said valve element and valve seat to prevent upward movement offluid past said drill collar within said casing, whereby fluid pressureexerted below said drill collar will raise the drill collar through thecasing.

References Cited in the file of this patent UNITED STATES PATENTS1,528,560 Myers et a1. Mar. 3, 1925 2,117,536 Baker et al May 17, 19382,286,126 Thornhill June 9, 1942 2,325,556 Taylor et al July 27, 1943

3. A REMOVABLE DRILL COLLAR FOR A STRING OF DRILLING CASING COMPRISING ATUBULAR MEMBER ADAPTED TO FIT SLIDABLY WITHIN SAID CASING, AN INVERTEDFRUSTO-CONICAL VALVE SEAT OF FLEXIBLE RESILIENT MATERIAL POSITIONEDWITHIN AND FASTENED TO SAID TUBULAR MEMBER, SAID VALVE SEAT HAVING ACENTRAL OPENING AT ITS LOWER END, A PLURALITY OF CIRCUMFERENTIALLYARRANGED RIGID RIBS EMBEDDED IN SAID VALVE SEAT MATERIAL, THE UPPER ENDOF EACH OF SAID RIBS BEING PIVOTALLY FASTENED TO SAID TUBULAR MEMBER, ABALL SHAPED VALVE ELEMENT FREELY MOVABLE WITHIN SAID TUBULAR MEMBER,SAID VALVE ELEMENT HAVING A DIAMETER GREATER THAN THE OPENING OF SAIDVALVE SEAT WHEREBY SAID RIBS WILL MOVE OUTWARD TO ENLARGE SAID OPENINGSUFFICIENTLY TO PASS SAID ELEMENT WHEN A DOWNWARD FORCE IS EXERTEDTHEREON, BUT WILL MOVE INWARDLY TO PREVENT UPWARD RETURN OF SAID ELEMENTWHEN AN UPWARD FORCE EXERTED ON SAID ELEMENT PLACES SAID ELEMENT INSEALING ENGAGEMENT TO PREVENT SEAT, A STOP MEMBER POSITIONED WITHIN SAIDTUBULAR MEMBER BELOW SAID VALVE SEAT AND ARRANGED TO PREVENT FURTHERDOWNWARD TRAVEL OF SAID VALVE ELEMENT AFTER IT HAS PASSED THROUGH SAIDOPENING, AND AT LEAST ONE RESILIENT SEAL FIXED TO THE